Method of rolling zinc slabs



O. P. LUETSCHER ET AL METHOD OF ROLLING- Z INC 'SLABS Filed Aug. 24- 1923 2 Sheets-Sheet 1 UEWSS oo g g m QN NN MN Q OA Feb, 10, 1925. 1,525,456

o. P. LUET SCHER ET AL METHOD OF ROLLING ZINC S LABS Filed Aug. 24. 3 2 Shoete-Sheet 2 /N/T\/A\L ROLL DIRECTION OF mu 1. nva

Patented eb. it), 1925;

ETE ED I tee ifi.

OLIVER P. LUETSCHER, OF PITTSBURGH, AND FLOIlEtEhl'CIE C. BIGGERT, JR., OF GRAFTON, I PENNSYLVANIA. y

METHOD OF ROLLING ZINC SLABS.

Application filed. August 24, 1923. Serial No..659,18

To all who-m it may con-mm:

Be it known that we. OLIVER P. Ltrnrscrrnn and FLORENCE BEGGERT. J12, residing at Pittsburgh and Grafton, respectively. county of Allegheny, and State of Pennsylvania, have invented new and useful Improvements in Methods of Rolling Zinc Slabs, of which the following is a full, clear, and exact description.- i

The present invention relates broadly to metal working. and more particularly to. a.

method adapted especially to the rolling of non-ferrous metals. such as zinc slabs. into thin gauge sheet or strip form.

At the present time. it is customary in the art to which this invention relates to take the zinc slabs as they are cast and pass the same to an annealing furnace in which they are raised to the proper temperature. From the annealing furnace, the slabs, are taken. two at a time, to a roughing mill. Those are taken by the rougher who places them on the fore plate of an ordinary two high mill with their long dimensions parallel to the axes of the rolls. The first slab is then pushed through the mill where it iscaught by a catcher on the other side and lifted to the top of the upper roll. The rougher then passes the second slab through the mill and takes the first slab from the catcher and drops it to the fore plate ready for the next pass between the rolls. This operation is repeated as many times as is necessary to roll the slabs tothe desired thickness, the rolls being screwed blanks.

down between successive passes. The last pass is usually made with the two rough sheets, as the slabs have become by that time, placed one on top of the other and rolled as one sheet.

Being hand work, this method'of rolling is a laborious operation, requiring considerable tune and the service of a number of men by reason of the fact that it isexthe same in other ways. I

In the copending application of Oliver P. Luetscher, Serial No. 636,857, 'filed May 5, 1923, there is disclosed a method of forming perfect slabs having much greater dimensions than has heretofore been considered -,1"easible, and of such weight that they cannot be effectively handled manual- The production of slabs of this character has made it possible to improve the the limits of our invention. as changes may I obviously be made therein without departing from the spirit of the invention or scope of our broader claims. In the drawings,

Figure 1 is a side elevation, partly broken away, illustrating a portion of an anneal mg furnace together with a portion of a roll ing mill;

Figure 2 is a detail view of a portion of the furnace structure illustrated in Fig ure 1;

Figure 3 is adiagrammatic top plan View of a portion of the finishing mill;

Figure 4 is a side elevation of the construction illustrated in Figure 3; i

Figure 5 is a side elevation, similar to Figure 3, illustrating a slightly modified form of the invention;

Figure 6 is atop plan view of a plate indicating in dotted lines one method of shearing the same to form blanks for strip rolling; and

Figure 7 is a similar View of one of the In carrying out the present invention, the slabs 2, which may have a weight well in excess of 100 pounds, making them too heavy to be effectively handled manually, may be forced by suitable charging mechanism 3 onto the supporting rails 4 of an annealing furnace 5. The charging mechanism is operative to gradually force the slabs through the'furnace towards the discharge end thereof.

Heretofore it has been customary to take. the smaller slabs as produced, load the same 1 onto cars, and pass the cars through the annealing furnace- Due to the com aratively small mass of such slabs, it as been found necessary to add considerable heat thereto in the furnace. By the present invention, by reason of the increased size of the slabs, it has been found that sufici enti heat may be retained thereby so that in some cases it may be desirable to cool the same, For this purpose, the furnace may be provided with a series of shutters or doors 7 connected in any desired manner to a thermostatic operating mechanism 8,

whereby when the temperature within the furnace exceeds a predetermined point, the

shutters will be automatically opened to per- 10 mit the passage of an increased amount of air to the furnace.

In cases, howe\'er,'where ahigher temperature is desired, this may be obtained by suitable burners or electrical heating means 9, the circuit to which may be controlled by the thermostat 8, as well understood in the art, so as to close the circuit when the temperature within the furnace falls below a predetermined point.

The slabs at the proper temperature are then successively withdrawn from the annealing furnace and passed in known mannor to the table 10 of a three high mill 11. Preferably, this mill will be of the character in which the center roll is provided with means for raising or lowering the same to permit the entry of the slabs therebetween and insure the proper reduction thereof. The rolled slabs are receive by the table 12 and returned as is custo ary in the art, until there-is produced a sheet. having the desired thickness.

The sheetafter this rough rolling is in the form of a wide strip having a. width 5 substantially equal to, or slightly greater than, the length of the o iginal slab. This strip is then passed o rotary shearing means 13 by means of which both edges are trimmed'to provide a sheet of the de- 40 sired'width. This strip, in this form, may

either be sheared into lengths for the forma- -tion of packs suitable for finishing by the present-method, or coiled for transportation or storage, as may be deemed advisable.

Preferably, however, each individual sheet with its edges sheared and trimmed is carried from the rotary shear to a series of finishing-mills 14 arranged in tandem. Each of these mills will give the sheet a single pass, and their number, therefore,

should be equal to the number of passes it is desired to give the sheet.

In rolling by this method, I have found it very desirable toprovide means to maintain a tension on both the entering and delivery side of the mill. For this purpose, as shown in Figures 3 and 4, the mills may each be provided with wedge guides 15 on the entering sides and with a power driven 6 reel or coiler 16 at the delivery end of the mill. To the accomplishment of this end,

' 'each mill should, preferably be driven by separate motor 17 to allow any desired speed ratio to be maintained between the rolls of the different stands. In Figure 5 there is illustrated a slightly modified form of tension device 15' at the entering side of each mill.

In some cases it may be desirable to add or subtract heat to or from the sheet during the finish rolling thereof. For this purpose, there may be provided suitable heating or cooling means l8 b.etween the successive roll stands. utilized for heating, may be broadly of the character disclosed in the copending application of Florence C. Biggert, Serial No.

This means, where 607,454, filed December 16, 1922, or of any other desired construction.

Illth event it is desired to produce. a

sheet havinga width greater than the length of the initial slab, the slab may be passed through the mill cornerwise on the alternate diagonals for any desired number of i passes. This process will have the further advantage of improving the texture of the metal, due to the cross rolling thereof, or the working in opposite directions.

The product-ion of a single sheet of the character herein recited possess many ad-- vantages, not only in the ease of operation.

as clearly pointed out, but in the factthat a uniform product is insured. Each sheet so produced may e cut into a series of in dividual pieces of a size suitable for forming a pack and an entire pack formed from a single sheet. In this manner, absolute uniformity, both as to thickness and temper, between the initial sheets of each pack is insured, and, therefore much greater uni.- formity in the finished product is made possible. Ileretofore, where each sheet in the ack has been individually rolled, any (BIIOIKQI' variation in the sheets has been maintained throughout the entire rolling operation. r

The present invent-ion also lends itself admirably to the production of strips. In rolling strips, a rough rolled plate S, as shown, in Figure 6. either with or without a series of strips or blanks B, as indicated by dotted lines. It will be apparent that during the formation of the sheet S, it

was rolled generally in the direction of the arrows at. During the rolling of the blanks B to reduce them to the desired thickness,

they will be rolled at substantially right 110 its opposite edges trimmed,may he cut into 4 zation of heavier slabs than it has hereto-- .fore been possible to make.

Furtheradvantages arise from the pro- VlSlOll of a substantial continuous process for the rolling of zinc. whereby the amount of manual labor and the time required to effect the necessary rolling operations are both reduced.

Further advantages arise from a method by which it is possible to form a pack of sheets produced entirely from a single body of metal having uniform thickness.

We claim:

1. In the method of rolling zinc slabs into thin gauge sheets, the steps consisting in forming a slabhaving a weight too great to be effectively handled manually, reducing the same in a three high mill, trimming the edges of the rough sheet, and then reducing the rough sheet to the desired thickness by passing the-same successively through a series of finishing mills.

2. In the method of rolling zinc slabs into thin gauge sheets, the steps consisting in orming a slab having a weight too great to be effectively handled manually, reducing the same in a three high mill, trimming the edges of the rough sheet, then reducing the rough sheet to the desired thickness by passing the same successively through a series of finishing mills, and effecting a heat interchange between said mills.

In the method of rolling zinc slabs into thin gauge sheets, the steps consisting in forming a slab having a weight too great to beeffectively handled manually, reducing the same in a three high mill, trimming the edges of the rough sheet, then reducing the rough sheet to the desired thickness by passing the same successively through a series of finishing mills, and maintaining a tension.

on the sheet during its passagethroug'h all of said mills. a

4. In the method. of rolling zinc slabs into thin gauge sheets, the st'e s consisting in forming a slab having a weight too great to be 'efiectively handled manually, reducing the same in a three high mill, trimming the edges of the rough sheet, and then reducing the rough sheet to the desired thickness by passin the same as an individual sheet successive y through a series of finishing mills.

5. In the method of rolling non-ferrous metals, the steps consisting in forming a slab, and rolling the same into a rough sheet by alternate passes on different diagonals.

6. In the method of rolling non-ferrous metals, the steps consisting in forming a slab, rolling the'same into a rough sheet, passing the same as an individual sheet through a plurality of finishing mills, and maintaining tension both on the entering and exit sides of at least some of said mills.

7. In the method of rolling non-ferrous metals, the steps consisting in forming a slab, rolling the same into a rough sheet, passing the same through a plurality of finishing mills, and maintaining tension both on the entering and exit sides of at least some of said mills.

8. In the method of rolling non-ferrous metals, the. steps consisting in forming a slab, rolling the same into a rough sheet,

passing the same through a plurality of finishing mills, maintaining tension both on the entering and exit sides of at least some of said mills, and efi'ecting'a heat interchange between some of said mills.

9. In the method of rolling non-ferrous metals, the steps consisting in forming a sheet by passing a slab through a series of finishing mills under tension, and coiling the sheet while under tension.

10. In the method of rolling non-ferrous metals, the steps consisting in forming a rough sheet, shearing the same to form a plurality of sheets, superimposing said sheets to form a pack, and then rolling said pack.

11. In the method of rolling zinc, the

imposing said sheets to form a pack, and

then rolling the pack.

In testimony whereof we have hereunto setour hand.

. OLIVER P. LUETSCHER.

FLORENCE C: BIGGERT, JR. 

